Along with the development of the Internet, electronic information is shared by Internet users all over the world. People can obtain various kinds of information from the Internet at any time to the benefit of their learning and other aspects of the life. Certain Internet communication software and services (e.g., QQ and MSN) have become a part of Internet users' lives including work, learning and entertainment. Because Internet communication often requires transmitting a file, file transmission has become one of the most important applications in the Internet.
File transmission as a core application of Internet application is also supported by operating systems such as Windows. Mainstream operating systems such as Windows already have support for transmission of files and file folders by means of network sharing in their various versions. However, such file and file folder transmission can only be carried out efficiently within a local area network. At the same time, in order to satisfy needs of Internet users, instant messaging software applications have provided a more powerful file transmission function using P2P (peer to peer networking) and file relay technology to realize transmission of a file between any two ends or even multiple ends on the Internet. However, because the transmission of a file folder is more complicated, existing instant messaging software has so far not provided a function for file folder transmission.
In a practical application, an Internet user often needs to send all files under a specific file folder. Because existing instant messaging tools do not provide a function for fast and simple file folder transmission, the user usually completes the transmission of a file folder using one of the following approaches.
In a first approach, a sender selects a file folder to be sent, and zips all the files in the file folder using zip software. After zipping is completed, a single zip file is sent to the recipient. Upon receiving the zip file, the recipient unzips the file to recover the file folder.
In particular, a Chinese patent Application No. 200310112571.6 discloses a proxy system and a method for file transmission. The method disclosed therein allows a proxy server to download information from a FTP (File Transfer Protocol) server, and upload information to the FTP server, based on a user request sent from a client computer. As shown in FIG. 1, the file transmission proxy system includes a proxy server 101, multiple client computers 103, a network 104, and a FTP server 102. As shown in FIG. 2, the proxy server 201 (101) includes a transmission module 210, a compression module 211, a decompression module 212, and a connecting module 213. The transmission module 210 is used for transmitting information between a client computer 103 and the FTP server 102. The compression module 211 is used for compressing the information that is being sent to a client computer 103. The decompression module 212 is used for decompressing the information that is being sent to the FTP server 102. The connecting module 213 is used for connecting with the FTP server 102 according to a request from a user. Using the system disclosed therein can improve file transmission speed, and file transmission security.
By zipping and compressing files in a file folder before transmission, the above-disclosed system and method not only have fast transmission speed, but also have lower costs for technical implementation. However, for a file folder of large size, zipping and unzipping become time-consuming. This causes a large amount of CPU, hard disk and memory resources of a user computer to be occupied during the process, and a poor user experience.
In an alternative approach, the sender selects and sends files in a file folder one after one, and the recipient receives the files one by one until the transmission of all the files is completed. Although this transmission method does not require zipping and has a low cost for technical implementation, the user operations of both the sender and the recipient can be extremely tedious. A large amount of time and energy can be wasted if a file folder contains a large number of files. Moreover, the complexity of network environment for a user, and the uncertainty of the user operations in a transmission process (e.g., sudden Internet failure or wrong file selection by the user) have posed difficulties to this method. Furthermore, because the Windows operating system has a maximum limit of 260 letters for a directory length, if the depth of a sub-directory of a file folder being sent (i.e., the maximum path length of a file in the file folder) is exceedingly deep, a storage failure for a recipient will occur. If the network conditions of two file transmission ends are poor, frequent fluctuations of data transmission routes may terminate the connection, and cause difficulties in recovering previous transmission after re-connection.